Plasma apolipoprotein A1 levels at diagnosis are independent prognostic factors in invasive ductal breast cancer.

Strong evidence exists indicating that the risk of breast cancer (BC) occurrence is influenced by complex internal environmental factors, including blood lipid and lipoprotein components. However, the roles of these components in BC development and progression remain controversial. This study examined whether serial serum lipid and lipoprotein measurements were associated with breast cancer risk and whether lipoproteins had BC prognostic properties. We compared the plasma-related parameter levels, including lipid and lipoprotein levels between 299 patients with invasive ductal breast cancer, also known as invasive ductal carcinoma (IDC), and 200 healthy donors. We performed univariate and multivariate logistic regression analyses to assess overall survival (OS) and disease-free survival (DFS). We found that the serum glucose, triacylglycerol, and low-density lipoprotein levels were significantly higher in patients with IDC than in healthy donors. However, high-density lipoprotein and apolipoprotein A1 (apoA1) levels were lower in patients with IDC than in healthy donors. Multivariate regression analysis demonstrated that elevated apoA1 levels were associated with a reduced risk of IDC, and univariate analysis showed that patients with IDC with lower apoA1 levels at diagnosis had larger tumors than patients with high apoA1 levels. Moreover, patients with IDC with lower apoA1 levels were more likely to have positive axillary lymph nodes, and were diagnosed at more advanced disease stages than patients with high apoA1 levels. We used a Cox regression model to assess the relationships between the above parameters and DFS and OS, after adjusting for tumor T and N stages, which were determined using the TNM classification system, and immunohistochemical subtypes. We found that lower apoA1 levels at diagnosis were associated with poor DFS and OS. At 60 months of follow-up, the DFS rate is 74.5% in the apoA1 L1 group, 89.9% in apoA1 L2 group, and 93.1% in apoA1 L3 group (p=0.0002). Similarly, the OS rate is 78.2% in apoA1 L1 group, 91.3% in apoA1 L2 group, and 93.7% in apoA1 L3 group (p=0.0012). In conclusion, our data indicate that low apoA1 levels are an independent predictor of the poor clinical outcomes in IDC patients.